Recent developments in the field of endoscopic surgical techniques and medical devices have provided the skilled otorhinolaryngologist with instrumentation and methods to perform complex paranasal sinus surgical procedures. Improved visualization of the nasal cavity and paranasal sinuses now make these anatomical areas more accessible to the endoscopic surgeon. Surgical guidelines for performing these operations are described in "Endoscopic Paranasal Sinus Surgery" by D. Rice and S. Schaefer, Raven Press, 1988) and in the writings of M. E. Wigand, Messerklinger and Stamberger. Various procedures, such as anterior and posterior ethmoidectomy, sphenoidectomy, maxillary antrostomy, frontal sinusotomy, etc., may be performed in these areas.
For instance, the Wigand procedure typically involves transection of the middle turbinate, beginning with the posterior aspect, visualization of the sphenoid ostium and opening of the posterior ethmoid cells for subsequent surgery. In the sphenoidectomy step, the ostium of the sphenoid is identified and the anterior wall of the sinus removed. Following this step, the posterior ethmoid cells may be entered at their junction with the sphenoid and the fovea ethmoidalis can be identified as an anatomical landmark for further dissection. In anterior ethmoidectomy, the exenteration of the ethmoids is carried anteriorly to the frontal recess. Complications, such as hemorrage, infection, perforation of the fovea ethmoidalis or lamina papyracea, and scarring or adhesion of the middle turbinate, are reported in connection with these procedures.
A particular problem encountered by the endoscopic surgeon has been postoperative adhesion occurring between the middle turbinate and adjacent nasal areas, such as medial adhesion to the septum and lateral adhesion to the lateral nasal wall in the area of the ethmoid sinuses. Otherwise successful surgical procedures may have poor results in these cases. Some surgeons have proposed amputation of the lower half of the middle turbinate at the conclusion of surgery to avoid this complication, resulting in protracted morbidity (crust formation and nasal hygiene problems). The turbinate adhesion problem detracts from an otherwise refined endoscopic surgical procedure.
In an attempt to avoid adhesions, surgeons may often pack the operative site with non-fiber, hydratable and expandable packing, or other materials such as tampons. A "sinus pack" tampon, such as disclosed in U.S. Pat. No. 4,646,739, may be used for short term packing of the operative site; however, risk of `toxic shock syndrome` after only a day or two is significant. The use of post-operative packing, such as "Merocel Sinus-Pak", is reported to prevent lateralization of the middle turbinate while packing the osteomeatal complex. Packing can displace the middle turbinate in a medial direction and carries with it a significant risk of having the turbinate adhere to the nasal septum, with resultant airway obstruction. While various septal splints can prevent adhesions to the nasal septum, adhesions of the lateral aspect of the middle turbinate to the lateral ethmoid sinus wall are not prevented concurrently.
It is an object of the present invention to provide a sheath device for application to the post-operative middle turbinate, which is effective to prevent both nasal septum and side wall adhesion for at least seven days during healing.